Kafka in Kubernetes - Marking the coordinator dead for group

Question

I am pretty new to Kubernetes and wanted to setup Kafka and zookeeper with it. I was able to setup Apache Kafka and Zookeeper in Kubernetes using StatefulSets. I followed this and this to build my manifest file. I made 1 replica of kafka and zookeeper each and also used persistent volumes. All pods are running and ready.

I tried to expose kafka and used Service for this by specifying a nodePort(30010). Seemingly this would expose kafka to the outside world where they can send messages to the kafka broker and also consume from it.

But in my Java application, I made a consumer and added the bootstrapServer as <ip-address>:30010, the following logs were displayed:

INFO o.a.k.c.c.i.AbstractCoordinator - Discovered coordinator kafka-0.kafka-hs.default.svc.cluster.local:9093 (id: 2147483647 rack: null) for group workerListener.
INFO o.a.k.c.c.i.AbstractCoordinator - Marking the coordinator kafka-0.kafka-hs.default.svc.cluster.local:9093 (id: 2147483647 rack: null) dead for group workerListener

Interestingly, when I tested the cluster using kubectl commands, I was able to produce and consume messages:

kubectl run -ti --image=gcr.io/google_containers/kubernetes-kafka:1.0-10.2.1 produce --restart=Never --rm \
 -- kafka-console-producer.sh --topic test --broker-list kafka-0.kafka-hs.default.svc.cluster.local:9093 done;

kubectl run -ti --image=gcr.io/google_containers/kubernetes-kafka:1.0-10.2.1 consume --restart=Never --rm -- kafka-console-consumer.sh --topic test --bootstrap-server kafka-0.kafka-hs.default.svc.cluster.local:9093

Can someone point me in the right direction why it is marking the coordinator as dead?

kafka.yml

apiVersion: v1
kind: Service
metadata:
  name: kafka-hs
  labels:
    app: kafka
spec:
  ports:
  - port: 9093
    name: server
  clusterIP: None
  selector:
    app: kafka
---
apiVersion: v1
kind: Service
metadata:
  name: kafka-cs
  labels:
    app: kafka
spec:
  type: NodePort
  ports:
  - port: 9093
    nodePort: 30010
    protocol: TCP
  selector:
    app: kafka
---
apiVersion: apps/v1beta1
kind: StatefulSet
metadata:
  name: kafka
spec:
  serviceName: kafka-hs
  replicas: 1
  podManagementPolicy: Parallel
  updateStrategy:
    type: RollingUpdate
  template:
    metadata:
      labels:
        app: kafka
    spec:
      affinity:
        podAntiAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            - labelSelector:
                matchExpressions:
                  - key: "app"
                    operator: In
                    values:
                    - kafka
              topologyKey: "kubernetes.io/hostname"
        podAffinity:
          preferredDuringSchedulingIgnoredDuringExecution:
             - weight: 1
               podAffinityTerm:
                 labelSelector:
                    matchExpressions:
                      - key: "app"
                        operator: In
                        values:
                        - zk
                 topologyKey: "kubernetes.io/hostname"
      terminationGracePeriodSeconds: 300
      containers:
      - name: k8skafka
        imagePullPolicy: Always
        image: gcr.io/google_containers/kubernetes-kafka:1.0-10.2.1
        resources:
          requests:
            memory: "1Gi"
            cpu: "0.5"
        ports:
        - containerPort: 9093
          name: server
        command:
        - sh
        - -c
        - "exec kafka-server-start.sh /opt/kafka/config/server.properties --override broker.id=${HOSTNAME##*-} \
          --override listeners=PLAINTEXT://:9093 \
          --override zookeeper.connect=zk-cs.default.svc.cluster.local:2181 \
          --override log.dir=/var/lib/kafka \
          --override auto.create.topics.enable=true \
          --override auto.leader.rebalance.enable=true \
          --override background.threads=10 \
          --override compression.type=producer \
          --override delete.topic.enable=false \
          --override leader.imbalance.check.interval.seconds=300 \
          --override leader.imbalance.per.broker.percentage=10 \
          --override log.flush.interval.messages=9223372036854775807 \
          --override log.flush.offset.checkpoint.interval.ms=60000 \
          --override log.flush.scheduler.interval.ms=9223372036854775807 \
          --override log.retention.bytes=-1 \
          --override log.retention.hours=168 \
          --override log.roll.hours=168 \
          --override log.roll.jitter.hours=0 \
          --override log.segment.bytes=1073741824 \
          --override log.segment.delete.delay.ms=60000 \
          --override message.max.bytes=1000012 \
          --override min.insync.replicas=1 \
          --override num.io.threads=8 \
          --override num.network.threads=3 \
          --override num.recovery.threads.per.data.dir=1 \
          --override num.replica.fetchers=1 \
          --override offset.metadata.max.bytes=4096 \
          --override offsets.commit.required.acks=-1 \
          --override offsets.commit.timeout.ms=5000 \
          --override offsets.load.buffer.size=5242880 \
          --override offsets.retention.check.interval.ms=600000 \
          --override offsets.retention.minutes=1440 \
          --override offsets.topic.compression.codec=0 \
          --override offsets.topic.num.partitions=50 \
          --override offsets.topic.replication.factor=3 \
          --override offsets.topic.segment.bytes=104857600 \
          --override queued.max.requests=500 \
          --override quota.consumer.default=9223372036854775807 \
          --override quota.producer.default=9223372036854775807 \
          --override replica.fetch.min.bytes=1 \
          --override replica.fetch.wait.max.ms=500 \
          --override replica.high.watermark.checkpoint.interval.ms=5000 \
          --override replica.lag.time.max.ms=10000 \
          --override replica.socket.receive.buffer.bytes=65536 \
          --override replica.socket.timeout.ms=30000 \
          --override request.timeout.ms=30000 \
          --override socket.receive.buffer.bytes=102400 \
          --override socket.request.max.bytes=104857600 \
          --override socket.send.buffer.bytes=102400 \
          --override unclean.leader.election.enable=true \
          --override zookeeper.session.timeout.ms=6000 \
          --override zookeeper.set.acl=false \
          --override broker.id.generation.enable=true \
          --override connections.max.idle.ms=600000 \
          --override controlled.shutdown.enable=true \
          --override controlled.shutdown.max.retries=3 \
          --override controlled.shutdown.retry.backoff.ms=5000 \
          --override controller.socket.timeout.ms=30000 \
          --override default.replication.factor=1 \
          --override fetch.purgatory.purge.interval.requests=1000 \
          --override group.max.session.timeout.ms=300000 \
          --override group.min.session.timeout.ms=6000 \
          --override inter.broker.protocol.version=0.10.2-IV0 \
          --override log.cleaner.backoff.ms=15000 \
          --override log.cleaner.dedupe.buffer.size=134217728 \
          --override log.cleaner.delete.retention.ms=86400000 \
          --override log.cleaner.enable=true \
          --override log.cleaner.io.buffer.load.factor=0.9 \
          --override log.cleaner.io.buffer.size=524288 \
          --override log.cleaner.io.max.bytes.per.second=1.7976931348623157E308 \
          --override log.cleaner.min.cleanable.ratio=0.5 \
          --override log.cleaner.min.compaction.lag.ms=0 \
          --override log.cleaner.threads=1 \
          --override log.cleanup.policy=delete \
          --override log.index.interval.bytes=4096 \
          --override log.index.size.max.bytes=10485760 \
          --override log.message.timestamp.difference.max.ms=9223372036854775807 \
          --override log.message.timestamp.type=CreateTime \
          --override log.preallocate=false \
          --override log.retention.check.interval.ms=300000 \
          --override max.connections.per.ip=2147483647 \
          --override num.partitions=1 \
          --override producer.purgatory.purge.interval.requests=1000 \
          --override replica.fetch.backoff.ms=1000 \
          --override replica.fetch.max.bytes=1048576 \
          --override replica.fetch.response.max.bytes=10485760 \
          --override reserved.broker.max.id=1000 "
        env:
        - name: KAFKA_HEAP_OPTS
          value : "-Xmx512M -Xms512M"
        - name: KAFKA_OPTS
          value: "-Dlogging.level=INFO"
        volumeMounts:
        - name: kafka-pv-volume
          mountPath: /var/lib/kafka
        readinessProbe:
          exec:
           command:
            - sh
            - -c
            - "/opt/kafka/bin/kafka-broker-api-versions.sh --bootstrap-server=localhost:9093"
      securityContext:
        runAsUser: 0
        fsGroup: 1000
  volumeClaimTemplates:
  - metadata:
      name: kafka-pv-volume
    spec:
      storageClassName: manual
      accessModes: [ "ReadWriteOnce" ]
      resources:
        requests:
          storage: 1Gi

zookeeper.yml

apiVersion: v1
kind: Service
metadata:
  name: zk-hs
  labels:
    app: zk
spec:
  ports:
  - port: 2888
    name: server
  - port: 3888
    name: leader-election
  clusterIP: None
  selector:
    app: zk
---
apiVersion: v1
kind: Service
metadata:
  name: zk-cs
  labels:
    app: zk
spec:
  ports:
  - port: 2181
    name: client
  selector:
    app: zk
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: zk
spec:
  selector:
    matchLabels:
      app: zk
  serviceName: zk-hs
  replicas: 1
  updateStrategy:
    type: RollingUpdate
  podManagementPolicy: Parallel
  template:
    metadata:
      labels:
        app: zk
    spec:
      affinity:
        podAntiAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            - labelSelector:
                matchExpressions:
                  - key: "app"
                    operator: In
                    values:
                    - zk
              topologyKey: "kubernetes.io/hostname"
      containers:
      - name: kubernetes-zookeeper
        imagePullPolicy: Always
        image: "k8s.gcr.io/kubernetes-zookeeper:1.0-3.4.10"
        resources:
          requests:
            memory: "1Gi"
            cpu: "0.5"
        ports:
        - containerPort: 2181
          name: client
        - containerPort: 2888
          name: server
        - containerPort: 3888
          name: leader-election
        command:
        - sh
        - -c
        - "start-zookeeper \
          --servers=1 \
          --data_dir=/var/lib/zookeeper/data \
          --data_log_dir=/var/lib/zookeeper/data/log \
          --conf_dir=/opt/zookeeper/conf \
          --client_port=2181 \
          --election_port=3888 \
          --server_port=2888 \
          --tick_time=2000 \
          --init_limit=10 \
          --sync_limit=5 \
          --heap=512M \
          --max_client_cnxns=60 \
          --snap_retain_count=3 \
          --purge_interval=12 \
          --max_session_timeout=40000 \
          --min_session_timeout=4000 \
          --log_level=INFO"
        readinessProbe:
          exec:
            command:
            - sh
            - -c
            - "zookeeper-ready 2181"
          initialDelaySeconds: 10
          timeoutSeconds: 5
        livenessProbe:
          exec:
            command:
            - sh
            - -c
            - "zookeeper-ready 2181"
          initialDelaySeconds: 10
          timeoutSeconds: 5
        volumeMounts:
        - name: pv-volume
          mountPath: /var/lib/zookeeper
      securityContext:
        runAsUser: 0
        fsGroup: 1000
  volumeClaimTemplates:
  - metadata:
      name: pv-volume
    spec:
      storageClassName: manual
      accessModes: [ "ReadWriteOnce" ]
      resources:
        requests:
          storage: 1Gi

EDIT:

I changed log level to TRACE. These are the logs I got

2018-01-11 18:56:24,617 TRACE o.a.k.c.NetworkClient - Completed receive from node -1, for key 3, received {brokers=[{node_id=0,host=kafka-0.kafka-hs.default.svc.cluster.local,port=9093,rack=null}],cluster_id=LwSLmJpTQf6tSKPsfvriIg,controller_id=0,topic_metadata=[{topic_error_code=0,topic=mdm.worker.request,is_internal=false,partition_metadata=[{partition_error_code=0,partition_id=0,leader=0,replicas=[0],isr=[0]}]}]}
2018-01-11 18:56:24,621 DEBUG o.a.k.c.Metadata - Updated cluster metadata version 2 to Cluster(id = LwSLmJpTQf6tSKPsfvriIg, nodes = [kafka-0.kafka-hs.default.svc.cluster.local:9093 (id: 0 rack: null)], partitions = [Partition(topic = mdm.worker.request, partition = 0, leader = 0, replicas = [0], isr = [0])])
2018-01-11 18:56:24,622 TRACE o.a.k.c.NetworkClient - Completed receive from node -1, for key 10, received {error_code=0,coordinator={node_id=0,host=kafka-0.kafka-hs.default.svc.cluster.local,port=9093}}
2018-01-11 18:56:24,624 DEBUG o.a.k.c.c.i.AbstractCoordinator - Received GroupCoordinator response ClientResponse(receivedTimeMs=1515678984622, latencyMs=798, disconnected=false, requestHeader={api_key=10,api_version=0,correlation_id=0,client_id=consumer-1}, responseBody=FindCoordinatorResponse(throttleTimeMs=0, errorMessage='null', error=NONE, node=kafka-0.kafka-hs.default.svc.cluster.local:9093 (id: 0 rack: null))) for group workerListener
2018-01-11 18:56:24,625 INFO o.a.k.c.c.i.AbstractCoordinator - Discovered coordinator kafka-0.kafka-hs.default.svc.cluster.local:9093 (id: 2147483647 rack: null) for group workerListener.
2018-01-11 18:56:24,625 DEBUG o.a.k.c.NetworkClient - Initiating connection to node 2147483647 at kafka-0.kafka-hs.default.svc.cluster.local:9093.
2018-01-11 18:56:24,633 DEBUG o.a.k.c.NetworkClient - Error connecting to node 2147483647 at kafka-0.kafka-hs.default.svc.cluster.local:9093:
java.io.IOException: Can't resolve address: kafka-0.kafka-hs.default.svc.cluster.local:9093
    at org.apache.kafka.common.network.Selector.connect(Selector.java:195)
    at org.apache.kafka.clients.NetworkClient.initiateConnect(NetworkClient.java:762)
    at org.apache.kafka.clients.NetworkClient.ready(NetworkClient.java:224)
    at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.tryConnect(ConsumerNetworkClient.java:462)
    at org.apache.kafka.clients.consumer.internals.AbstractCoordinator$GroupCoordinatorResponseHandler.onSuccess(AbstractCoordinator.java:598)
    at org.apache.kafka.clients.consumer.internals.AbstractCoordinator$GroupCoordinatorResponseHandler.onSuccess(AbstractCoordinator.java:579)
    at org.apache.kafka.clients.consumer.internals.RequestFuture$1.onSuccess(RequestFuture.java:204)
    at org.apache.kafka.clients.consumer.internals.RequestFuture.fireSuccess(RequestFuture.java:167)
    at org.apache.kafka.clients.consumer.internals.RequestFuture.complete(RequestFuture.java:127)
    at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient$RequestFutureCompletionHandler.fireCompletion(ConsumerNetworkClient.java:488)
    at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.firePendingCompletedRequests(ConsumerNetworkClient.java:348)
    at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:262)
    at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:208)
    at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:184)
    at org.apache.kafka.clients.consumer.internals.AbstractCoordinator.ensureCoordinatorReady(AbstractCoordinator.java:214)
    at org.apache.kafka.clients.consumer.internals.AbstractCoordinator.ensureCoordinatorReady(AbstractCoordinator.java:200)
    at org.apache.kafka.clients.consumer.internals.ConsumerCoordinator.poll(ConsumerCoordinator.java:286)
    at org.apache.kafka.clients.consumer.KafkaConsumer.pollOnce(KafkaConsumer.java:1078)
    at org.apache.kafka.clients.consumer.KafkaConsumer.poll(KafkaConsumer.java:1043)
    at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.run(KafkaMessageListenerContainer.java:614)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.lang.Thread.run(Thread.java:748)
Caused by: java.nio.channels.UnresolvedAddressException: null
    at sun.nio.ch.Net.checkAddress(Net.java:101)
    at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:622)
    at org.apache.kafka.common.network.Selector.connect(Selector.java:192)
    ... 22 common frames omitted
2018-01-11 18:56:24,634 INFO o.a.k.c.c.i.AbstractCoordinator - Marking the coordinator kafka-0.kafka-hs.default.svc.cluster.local:9093 (id: 2147483647 rack: null) dead for group workerListener
2018-01-11 18:56:24,735 TRACE o.a.k.c.NetworkClient - Found least loaded node kafka-0.kafka-hs.default.svc.cluster.local:9093 (id: 0 rack: null)
2018-01-11 18:56:24,735 DEBUG o.a.k.c.c.i.AbstractCoordinator - Sending GroupCoordinator request for group workerListener to broker kafka-0.kafka-hs.default.svc.cluster.local:9093 (id: 0 rack: null)
2018-01-11 18:56:24,735 DEBUG o.a.k.c.NetworkClient - Initiating connection to node 0 at kafka-0.kafka-hs.default.svc.cluster.local:9093.
2018-01-11 18:56:24,736 DEBUG o.a.k.c.NetworkClient - Error connecting to node 0 at kafka-0.kafka-hs.default.svc.cluster.local:9093:
java.io.IOException: Can't resolve address: kafka-0.kafka-hs.default.svc.cluster.local:9093
    at org.apache.kafka.common.network.Selector.connect(Selector.java:195)
    at org.apache.kafka.clients.NetworkClient.initiateConnect(NetworkClient.java:762)
    at org.apache.kafka.clients.NetworkClient.ready(NetworkClient.java:224)
    at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.trySend(ConsumerNetworkClient.java:408)
    at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:223)
    at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:208)
    at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:184)
    at org.apache.kafka.clients.consumer.internals.AbstractCoordinator.ensureCoordinatorReady(AbstractCoordinator.java:214)
    at org.apache.kafka.clients.consumer.internals.AbstractCoordinator.ensureCoordinatorReady(AbstractCoordinator.java:200)
    at org.apache.kafka.clients.consumer.internals.ConsumerCoordinator.poll(ConsumerCoordinator.java:286)
    at org.apache.kafka.clients.consumer.KafkaConsumer.pollOnce(KafkaConsumer.java:1078)
    at org.apache.kafka.clients.consumer.KafkaConsumer.poll(KafkaConsumer.java:1043)
    at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.run(KafkaMessageListenerContainer.java:614)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.lang.Thread.run(Thread.java:748)
Caused by: java.nio.channels.UnresolvedAddressException: null
    at sun.nio.ch.Net.checkAddress(Net.java:101)
    at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:622)
    at org.apache.kafka.common.network.Selector.connect(Selector.java:192)
    ... 15 common frames omitted
2018-01-11 18:56:24,737 TRACE o.a.k.c.NetworkClient - Removing node kafka-0.kafka-hs.default.svc.cluster.local:9093 (id: 0 rack: null) from least loaded node selection: is-blacked-out: true, in-flight-requests: 0
2018-01-11 18:56:24,737 TRACE o.a.k.c.NetworkClient - Least loaded node selection failed to find an available node
2018-01-11 18:56:24,738 DEBUG o.a.k.c.NetworkClient - Give up sending metadata request since no node is available

Answer 1

I had the same problem as you last week and solved it, so it's possible to expose Kafka outside Kubernetes!

Solution: In your Kafka broker-config.yaml you should map cluster external IP to your local DNS

kafka-I.kafka-hs.default.svc.cluster.local:9093

How To:

add those to your server.properties file:

listener.security.protocol.map=INTERNAL_PLAINTEXT:PLAINTEXT,EXTERNAL_PLAINTEXT:PLAINTEXT
inter.broker.listener.name=INTERNAL_PLAINTEXT

if you have an init which run before server.properties you should add those:

# add unique label to each pod
kubectl label pods ${HOSTNAME} kafka-set-component=${HOSTNAME}

EXTERNAL_LISTENER_IP=<YOUR_KUBERNETES_CLUSTER_EXTERNAL_IP>
EXTERNAL_LISTENER_PORT=$((30093 + ${HOSTNAME##*-}))

sed -i "s/#listeners=PLAINTEXT:\/\/:9092/listeners=INTERNAL_PLAINTEXT:\/\/0.0.0.0:9092,EXTERNAL_PLAINTEXT:\/\/0.0.0.0:9093/" /etc/kafka/server.properties
sed -i "s/#advertised.listeners=PLAINTEXT:\/\/your.host.name:9092/advertised.listeners=INTERNAL_PLAINTEXT:\/\/$HOSTNAME.broker.kafka.svc.cluster.local:9092,EXTERNAL_PLAINTEXT:\/\/$EXTERNAL_LISTENER_IP:$EXTERNAL_LISTENER_PORT/" /etc/kafka/server.properties

otherwise you should find a way to add replace configurations in your server.properties at runtime.

Notice that you must have those lines commented in your server.properties file

#listeners=PLAINTEXT://:9092
#advertised.listeners=PLAINTEXT://your.host.name:9092

Services: Create headless service to map local DNS and a service for each broker you have:

# A headless service to create DNS records
---
apiVersion: v1
kind: Service
metadata:
  name: broker
  namespace: kafka
spec:
  ports:
  - port: 9092
  # [podname].broker.kafka.svc.cluster.local
  clusterIP: None
  selector:
    app: kafka
---
apiVersion: v1
kind: Service
metadata:
  name: broker-0
  namespace: kafka
spec:
  type: NodePort
  ports:
  - port: 9093
    nodePort: 30093
  selector:
    kafka-set-component: kafka-0
---
apiVersion: v1
kind: Service
metadata:
  name: broker-1
  namespace: kafka
spec:
  type: NodePort
  ports:
  - port: 9093
    nodePort: 30094
  selector:
    kafka-set-component: kafka-1
---
apiVersion: v1
kind: Service
metadata:
  name: broker-2
  namespace: kafka
spec:
  type: NodePort
  ports:
  - port: 9093
    nodePort: 30095
  selector:
    kafka-set-component: kafka-2

Notes: - If you are running on GKE:

1. YOUR_KUBERNETES_CLUSTER_EXTERNAL_IP which declared in the server.properties init can be found via gcloud compute instances list
2. Also you must give permission to the firewall gcloud compute firewall-rules create kafka-external --allow tcp:30093,tcp:30094,tcp:30095